title: Subjective and objective learning effects dissociate in space and in time.
abstract: Perceptual learning not only improves sensitivity, but it also changes our subjective experience. However, the question of how these two learning effects relate is largely unexplored. Here we investigate how subjects learn to see initially indiscriminable metacontrast-masked shapes. We find that sensitivity and subjective awareness increase with training. However, sensitivity and subjective awareness dissociate in space: Learning effects on performance are lost when the task is performed at an untrained location in another quadrant, whereas learning effects on subjective awareness are maintained. This finding indicates that improvements in shape sensitivity involve visual areas up to V4, whereas changes in subjective awareness involve other brain regions. Furthermore, subjective awareness dissociates from sensitivity in time: In an early phase of perceptual learning, subjects perform above chance on trials that they rate as subjectively invisible. Later, this phenomenon disappears. Subjective awareness is thus neither necessary nor sufficient for achieving above-chance objective performance.
authors.affiliation: Department of Neurophysiology, Max Planck Institute for Brain Research, 60528 Frankfurt am Main, Germany. caspar.schwiedrzik@brain.mpg.de
authors.forename: Caspar M
authors.initials: CM
authors.lastname: Schwiedrzik
authors.forename: Wolf
authors.initials: W
authors.lastname: Singer
authors.forename: Lucia
authors.initials: L
authors.lastname: Melloni
mesh_terms: D030141:Feedback, Psychological; D006801:Humans; D007858:Learning / Q000502:physiology*; D010775:Photic Stimulation; D012684:Sensory Thresholds / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors